♻️refactor: 장르 max개수 수정 및 유저 닉네임 중복 확인 구현

src/main/java/com/seeat/server/domain/user/application/dto/request/UserSignUpRequest.java

@@ -38,7 +38,7 @@ public class UserSignUpRequest {
      * 좋아하는 영화 장르
      */
     @NotNull(message = "좋아하는 영화 장르는 필수입니다.")
-    @Size(min = 1, message = "최소 하나 이상의 장르가 필요합니다.")
+    @Size(min = 1, max = 3, message = "1개~3개 사이의 장르가 필요합니다.")
     @Schema(description = "유저가 선호하는 영화 장르", example = "[\"ACTION\", \"COMEDY\",\"SF\"]")
     private List<MovieGenre> genres;
 

src/main/java/com/seeat/server/domain/user/application/dto/response/UserNicknameResponse.java

@@ -0,0 +1,22 @@
+package com.seeat.server.domain.user.application.dto.response;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import lombok.Builder;
+
+@Builder
+@Schema(name = "[응답][유저] 유저 닉네임 중복 확인 Response",description = "유저 닉네임 중복 확인에 대한 DTO 입니다.")
+public record UserNicknameResponse(
+        @Schema(description = "중복 여부", example = "false")
+        boolean duplicated,
+        @Schema(description = "결과 메시지", example = "사용 가능한 닉네임입니다.")
+        String message
+) {
+
+    // 정적 팩토리 메소드
+    public static UserNicknameResponse from(boolean duplicated){
+        return UserNicknameResponse.builder()
+                .duplicated(duplicated)
+                .message("닉네임 사용 가능합니다.")
+                .build();
+    }
+}

src/main/java/com/seeat/server/domain/user/application/service/UserService.java

@@ -3,13 +3,15 @@
 import com.seeat.server.domain.theater.domain.entity.Auditorium;
 import com.seeat.server.domain.theater.domain.repository.AuditoriumRepository;
 import com.seeat.server.domain.user.application.dto.request.UserSignUpRequest;
+import com.seeat.server.domain.user.application.dto.response.UserNicknameResponse;
 import com.seeat.server.domain.user.application.usecase.UserUseCase;
 import com.seeat.server.domain.user.domain.entity.User;
 import com.seeat.server.domain.user.domain.entity.UserAuditorium;
 import com.seeat.server.domain.user.domain.entity.UserSocial;
 import com.seeat.server.domain.user.domain.repository.UserAuditoriumRepository;
 import com.seeat.server.domain.user.domain.repository.UserRepository;
 import com.seeat.server.domain.image.application.usecase.ImageUseCase;
+import com.seeat.server.global.response.CustomException;
 import com.seeat.server.global.response.ErrorCode;
 import com.seeat.server.global.service.RedisService;
 import com.seeat.server.global.util.JwtConstants;
@@ -55,6 +57,27 @@ public Optional<User> getUserByEmail(String email) {
         return repository.findByEmail(email);
     }
 
+    /**
+     * 닉네임 중복 확인 로직
+     *
+     * @param nickname 사용할 닉네임
+     * @return true, false
+     */
+    @Override
+    public UserNicknameResponse isNicknameDuplicated (String nickname){
+
+        Boolean response = repository.existsByNickname(nickname);
+
+        // 중복이면 에러처리
+        if (response){
+
+            throw new CustomException(ErrorCode.DUPLICATED_NICKNAME, null);
+        }
+
+        return UserNicknameResponse.from(repository.existsByNickname(nickname));
+    }
+
+
     /**
      * 가입한 소셜 종류와 소셜 ID으로 최초 로그인인지 확인 로직
      *

src/main/java/com/seeat/server/domain/user/application/usecase/UserUseCase.java

@@ -1,6 +1,7 @@
 package com.seeat.server.domain.user.application.usecase;
 
 import com.seeat.server.domain.user.application.dto.request.UserSignUpRequest;
+import com.seeat.server.domain.user.application.dto.response.UserNicknameResponse;
 import com.seeat.server.domain.user.domain.entity.User;
 import com.seeat.server.domain.user.domain.entity.UserSocial;
 import com.seeat.server.security.oauth2.application.dto.TempUserInfo;
@@ -15,6 +16,9 @@ public interface UserUseCase {
     // 이메일 중복 확인
     Optional<User> getUserByEmail(String email);
 
+    // 닉네임 중복 확인
+    UserNicknameResponse isNicknameDuplicated(String nickname);
+
     // 소셜ID, 소셜로 유저 가입유무확인
     Optional<User> getUserBySocialAndSocialId(UserSocial social, String socialId);
 

src/main/java/com/seeat/server/domain/user/domain/repository/UserRepository.java

@@ -16,6 +16,8 @@ public interface UserRepository extends JpaRepository<User, Long> {
 
     Optional<User> findByEmail(String email);
 
+    Boolean existsByNickname(String nickname);
+
     Optional<User> findByIdAndIsDeleteFalse(Long userId);
 
     List<User> findAllByIsDeleteTrueAndUpdatedAtBefore(LocalDateTime cutoffDate);

src/main/java/com/seeat/server/domain/user/presentation/UserController.java

@@ -1,6 +1,7 @@
 package com.seeat.server.domain.user.presentation;
 
 
+import com.seeat.server.domain.user.application.dto.response.UserNicknameResponse;
 import com.seeat.server.domain.user.application.usecase.UserUseCase;
 import com.seeat.server.domain.user.application.dto.request.UserSignUpRequest;
 import com.seeat.server.domain.user.domain.entity.UserRole;
@@ -53,6 +54,15 @@ public ApiResponse<Void> userSignUp(
         return ApiResponse.created();
     }
 
+    @GetMapping
+    public ApiResponse<UserNicknameResponse> userDuplicateNickname(@RequestParam String nickname){
+
+        UserNicknameResponse response = userService.isNicknameDuplicated(nickname);
+
+        return ApiResponse.ok(response);
+    }
+
+
     /**
      * 로그아웃시 refreshToekn 쿠키, redis 삭제
      *

src/main/java/com/seeat/server/domain/user/presentation/swagger/UserControllerSpec.java

@@ -1,15 +1,14 @@
 package com.seeat.server.domain.user.presentation.swagger;
 
 import com.seeat.server.domain.user.application.dto.request.UserSignUpRequest;
+import com.seeat.server.domain.user.application.dto.response.UserNicknameResponse;
 import com.seeat.server.global.response.ApiResponse;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.tags.Tag;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
 import jakarta.validation.Valid;
-import org.springframework.web.bind.annotation.PostMapping;
-import org.springframework.web.bind.annotation.RequestBody;
-import org.springframework.web.bind.annotation.RequestHeader;
+import org.springframework.web.bind.annotation.*;
 
 import java.io.IOException;
 
@@ -33,6 +32,19 @@ ApiResponse<Void> userSignUp(
             @RequestHeader String tempUserKey
     ) throws IOException;
 
+    /**
+     * 사용자 닉네임 중복확인 API
+     *
+     * @param nickname 사용할 닉네임
+     * @return true(중복), false(사용가능)
+     */
+    @GetMapping
+    @Operation(
+            summary = "닉네임 중복 확인",
+            description = "true면 닉네임 중복, false면 닉네임 사용 가능한 닉네임 중복 확인 기능입니다."
+    )
+    ApiResponse<UserNicknameResponse> userDuplicateNickname(@RequestParam String nickname);
+
     /**
      * 로그아웃 API
      *

src/main/java/com/seeat/server/global/response/ErrorCode.java

@@ -84,6 +84,9 @@ public enum ErrorCode {
     /** 최초 로그인 추가 정보 필요 */
     FIRST_LOGIN(1200, HttpStatus.NOT_FOUND, "최초 로그인유저이기에 추가정보기입이 필요합니다."),
 
+    /** 중복 확인 **/
+    DUPLICATED_NICKNAME(1300,HttpStatus.CONFLICT, "이미 사용 중인 닉네임입니다."),
+
     // ========================
     // 2000~2999 : 영화관 관련 에러
     // ========================

src/main/java/com/seeat/server/security/config/RequestMatcherHolder.java

@@ -30,6 +30,7 @@ public class RequestMatcherHolder {
 
             // 유저 관련
             new RequestInfo(POST, "/api/v1/users", null),
+            new RequestInfo(GET, "/api/v1/users", null),
             new RequestInfo(POST, "/api/v1/users/logout", USER),
             new RequestInfo(POST, "/api/v1/users/dev/long-token", null),